The advent of self-driving cars is raising questions in the insurance sector about who should pay when the vehicles crash and how insurers will set equitable rates.

When cars can operate themselves, the central question will be whether accidents are the manufacturer’s responsibility and therefore covered by product liability insurance or whether the fault would lie with the driver and be covered by personal auto insurance.

While even today’s most advanced cars aren’t fully autonomous, experts say such cars are coming and the insurance question will only become more urgent. When a Tesla crashed near Houston in April, killing the two occupants, the initial focus was on Tesla’s self-driving technology, prompting CEO Elon Musk to deny that the car in question had those capabilities.

Musk said data logs showed the car didn’t have a full self-driving computer installation and the automaker’s separate Autopilot feature wasn’t enabled. Tesla says Autopilot requires active driver supervision and that no Tesla cars are completely autonomous. Police said no one was in the driver’s seat when the car crashed into a tree.

But there are other examples of autonomous vehicles gone wrong. The National Highway Traffic Safety Administration said it launched investigations into 34 crashes related to advanced driver-assistance systems, mostly involving Tesla vehicles but some involving models from Cadillac, Volvo, Lexus and Navya, a French firm that is developing self-driving shuttles.

Robert Passmore, vice president of auto and claims policy at the American Property Casualty Insurance Association, a trade group, said if there isn’t a human driver to ask, insurers will need to collect information from vehicles such as speed and when systems became aware of the person, vehicle or object with which they collided. Most cars already keep information about crashes in an event data recorder.

The association is lobbying Congress to give insurers access to vehicle data, which it says will support increasing automation of cars.

Passmore said the coverage might vary by circumstance. For cars with advanced driver-assistance features, the driver is still “responsible for the overall operation,” so liability would fall under personal auto. If the vehicle malfunctioned, the manufacturer’s product liability could be invoked — as already happens with standard cars. But even with a fully autonomous vehicle, individuals could have liability exposure if they didn’t do maintenance such as installing software updates, he added.

Thomas B. Considine, CEO of the National Council of Insurance Legislators, said there aren’t yet legal or regulatory requirements related to personal insurance for autonomous vehicles. The Uniform Law Commission — an organization of legislators and their staffs, judges, lawyers and professors that drafts model laws when states are seeking uniformity — considered creating one. But it ultimately decided insurance issues were complex and outside its scope.

One reason is that the question isn’t yet ripe. There aren’t vehicles available yet with fully automated driving features, notes Bryant Walker Smith, a law professor at the University of South Carolina and expert on automated driving. Still, lawmakers are preparing for when they arrive.

Smith said Sens. John Thune, R-S.D., and Gary Peters, D-mich., are among many working on autonomous vehicle legislation in Congress. Both are members of the Commerce, Science and Transportation Committee.

Although there aren’t fully autonomous vehicles ready for purchase, there are many being tested and even a few taking passengers on roads in Arizona.

Waymo, Google’s self-driving car project that became a separate part of parent company Alphabet, offers a ride-hailing service near Phoenix with fully autonomous vehicles, meaning there’s no one in the driver’s seat.

The company is also testing the technology for trucking and local delivery.

Volvo preemptively announced in 2015 that it would accept full liability for cars in autonomous mode and still expresses that commitment.

“When the future autonomous driving feature has been rolled out and is in use after activation by its user, Volvo Cars will take full responsibility, and assume liability, for it,” spokesperson Russell Datz said in an email.

Ford Autonomous Vehicles, created in 2018, plans to launch self-driving services next year. The service will transport people and goods, but the company won’t disclose more details yet for competitive reasons, spokesperson Dan Pierce said in an email.